Refrigerating machine of the absorption type



Nov. 1, 1938. A. BIKKERS I 2,134,996

REFRIGERATING MACHINE OF THE ABSORPTION TYPE Filed April 22, 1957 ,9 a)\s //A fl'exa/aderfig y latory pipe and thence to Patented Nov. 1938UNITED sT TEs 2,134,996 BEFRIGERATING MACHINE OF THE ABSORPTION TYPEAlexander Bikkers,

Netherlands Application April 22,

The Hague,- Netherlands, assignor to Willem Frederik Pocl, Haarlcm,\

1937, Serial No. lsssss In the Netherlands April 29, 1936 5Claims.

This invention relates (to refrigerating machines of the absorption typeinwhich the pressures are equalized by means of the addition of inertgas;

In applicant's Patent No. 2,020,763 it has been suggested to provideboth the absorber and the evaporator with an individualcirculatory pipeand to interconnect said pipes by a suitable conduit, through whichrefrigerant vapour from the circulatory pipe of the evaporator difiusesinto that of the absorber. This patented construction has theinconvenience that a'certain amount of heat is necessarily transmittedfrom the absorber. through its circulatory pipe, to the second circutheevaporator, whereby the efliciency of the machine is impaired. Moreover,difiusion is a very slow process, so that the capacity of the machineunder consideration is relatively small.

My present invention has for its object to meet the objections stated.With this object in view, I

- matic drawing. on which:

suggest to provide the absorber with a circulatory pipe, part of whichis in direct contact with a wall portion of the evaporator andcommunicates therewith through a suitable opening, and to provide theevaporator with bafiles along which the liquid refrigerant from thecondenser is adapted to flow down so as to produce, within theevaporator, eddies whereby the refrigerant vapour is compelled to flowacross said opening. Owing to the fact that a rich mixture of inert gasand refrigerant vapour is thus caused to.continuously flow across theopening in the evaporator wall, said vapour is adapted to diffuse intothe circulatory pipe of the absorber through a conduit, the length ofwhich is practically nil, whereby a comparatively great amount of saidvapour ,is'conveyed perunit of time. I

It will be appreciated that the wall portion, which is common to theevaporator and the circulatory pipe of the absorber, may be very thin,sinceequal total pressures obtain on either side of said wall portion.

If the density of the refrigerant vapour, for instance ammonia, issmaller than that of the inert gas, for instance nitrogen, it isadvisable to provide the aforesaid opening near the top of theevaporator, as under said circumstances the refrigerant has the naturaltendency to rise. If, however, the inert gas is hydrogen, or helium, itis preferred for said opening to be located near the bottom of theevaporator.

In order that my invention may be well understood, reference is bad tothe annexeddiagram- Fig. 1 is an elevation, partly in section of arefrigerating machine in accordance with the invention, and

Fig. 2 is an elevation, partly in section of a modified evaporator.

In Fig. 1', the numeral 2 designates the insulated wall of a cabinet,the interior space I of which is to be cooled.

Mounted outside said cabinet is a boiler or gas expelling vessel 3provided with a heating device 4. This vessel is connected near its topwith a liquid separator 5 having a plurality of baiiles 6 andcommunicating, through 'a' pipe 1, with the condenser 8, of which thelower and the upper portions are connected with the evaporator l2through pipes 9 and I3, respectively.

The evaporator l2, which is mounted within the cabinet 2, is providedwith two horizontal partitions I, each having plain openings I6 and alsoopenings IS with upturned edges. The openings in the one partition aredisposedin staggered relation to those in the other. Near the top, oneof the side walls has an opening ll, through which the evaporatorcommunicates with the descending section 22 of pipe l8, I9, 20, 2|, 22,23, 24, the section I3l9 ,of which acts as an absorber. At the junctionbetween sections 24 and I8, said pipe opens into a vertical conduit 25,which has a horizontal extension 26 merging as' at 21 into, the boiler 3and is connected with the bottom portion of the evaporator I2 by a pipe28.

Near its bottom, the boiler 3 is connected, through a conduit 29, withan auxiliary gas expeller 30 provided with a heating device 3| andcommunicating at its top, through an ascending pipe 32, with a vessel 33mounted inside the vapour space of the boiler 3. Said vessel 33 is con-\nozzle opening into a mixing cone 38, which,

merges into a discharge cone 39 so as to form an injector, it beingunderstood that said cones form parts of the circulatory section pipeI8. Pipe 34 is, through a substantial partof its length, enclosedby-pipe '26, with which it forms a heat exchanger. Another heatexchanger is formed by sections 20 and'23 of the circulatory pipe.

Assuming the boiler 3 to be partly filled with a strong aqueous solutionof ammonia, the remaining space of the machine to be filled withcompressed nitrogen, the modus operandi will be as follows.

Owing to the .heat developed by. the device 4,

a circulatory.

' through the plain openings N5 of the upper parby the arrows.

tition onto the lower partition l4, through the plain openings 16 ofwhich, part of the liquid may fall onto the bottom of the evaporator.

In the vicinity of openings IS a very low temperature will be producedby sudden evaporation of 'the liquid refrigerant. Owing to the openingsl5 having upturned edges, no liquid refrigerant can flow therethrough,so that the temperature near these openings will not so abruptly bereduced, the result being that eddies and vortexes are produced in themixture of inert gas and refrigerant vapour, as indicated It will thusbe understood that a rich gaseous mixture will continuously flow acrossthe opening l1, so that the refrigerant vapour has ample of opportunityto diffuse into section 22 of the circulatory pipe, where it mixes withthepoor gaseous mixture flowing therethrough in downward direction, soas to be conveyed to the absorber l8, l9.

Any liquid refrigerant collecting on the bottom of the evaporator isdischarged through pipe 28 into conduit 25.

The heater 3| causes refrigerant vapour to be freed by the solutioncontained in the auxiliary boiler 30. Thereby, an emulsion of vapour andliquid is produced, and this emulsion rises through the narrow ascendingpipe 32, whereby poor liquor is discharged into vessel 33.

From this vessel, the poor liquor flows through pipe 34, 35, 36 into theabsorber section l9, whence it flows by gravity into section l8, whereit absorbs the refrigerant vapour supplied thereto by sections 22, 23,241. The rich liquor thus produced in the absorber is returned, throughthe conduit 25, 26, 21., to the boiler 3.

The refrigerant vapour collecting in the upper portion of vessel 33 isdischarged into the aborator.

sorber section l8 through the injector 31b, 38,. 39, whereby therequired circulation in the circulatory pipe is produced, it beingunderstood that the pressure obtaining in vessel 33 is sufflciently inexcess of that in the absorber in order that the injector may operate.This circulation causes the poor gaseous mixture coming from theabsorber to flow through pipe 22 across opening H, where it can take uprefrigerant vapour from the evaporator and convey it to the absorber.

Since the hot section of the circulatory pipe is in heat exchanginrelation with the cold section 23, it is impossible for any appreciableamount of heat to be transmitted to the evap- Pipe l3 equalizes thepressures obtaining in the condenser l and in the evaporator l2,respectively. This is necess ry in order that the evaporator may becontinuously supplied with liquid refrigerant and, consequently, theeddies required for conveying refrigerant vapour to the openings I'lmaybe produced without interruption..

Fig. 2 shows an alternative construction of the evaporator. Theevaporator 12 here is provided with. a plurality oi sloping baflles 40'mounte-l edges of the battles,

- the addition of inert ing with at different levels and in staggeredrelation with one another in such a manner that 11-11116 refrigerantdischarged by pipe 9 flows from he top portion of the upper baflle tothe lower portion thereof, thence 'falls on the next baflle, and so on.Consequently, very low' local temperatures will be produced in thevicinity of the lower owing to the sudden evap-. oration of liquidrefrigerant, thus causing the required eddies to set up. In thisalternative construction, the opening I1 is provided near the bottom ofthe evaporator, since this type of evaporator has been designed for arefrigerating machine in which hydrogen or helium is used as the inertgas.

What I claim is:

1. In a continuous absorption machine in whichthe pressures areequalized by means of gas, a gas expeller, a con-- denser, an evaporatorand an absorber intercon nected in series, a circulatory pipe on theabsorber and partly contacting with a wall portion of the evaporator, anopening in said wall portion to establish communication between theevaporator and circulatory pipe, and baflle means provided in theevaporator, said baifle means being adapted to compel liquid refrigerantdischarged from the condenser into the evaporator to flow towards thebottom of the evaporator in such a manner. as to produce eddies in thegaseous mixture and cause refrigerant vapour continuously to flow acrosssaid opening.

2. In a continuous absorption machine containing an inert gas equalizingthe differences in the refrigerant pressure, a gas expeller, acondenser, an evaporator and an absorber, a cir culatory passage on theabsorber partly contacting with a wall portion of the evaporator, anopening in said wall portion communicating with the said circulatorypassage and baille means provided in the evaporator, said baffle meansbeing provided with apertures so formed that the liquid refrigerantdischarged into the evaporator can fall through only some of saidapertures, but is positively prevented from falling through others, insuch a manner as to produce eddies in the gaseous mixture within theevaporator and cause mixture rich in refrigerant to flow across saidopening.

3. In a continuous absorption machine containing an inert gas equalizingthe differences in the refrigerant pressure, a gas expeller, acondenser, an evaporator and an absorber, a circulatory passage on theabsober partly contacta wall portion of the evaporator, an opening insaid wall portion communicating with the said circulatory passage, andbaflle means provided in the evaporator, said baflle means comprising ahorizontal partition provided with an aperture having upturned edges,preventing the liquid refrigerant discharged into the evaporator fromfalling through the said aperture, and further provided with an aperturethe edges of which are located at a lower level than those of the firstmentioned aperture to permit the said liquid to fall down through it,the said apertures arranged in such a manner as to produce eddies in thegaseous mixture within the evaporator and cause mixture rich inrefrigerant to flow across said opening. 1

4. In a continuous absorption machine containing an inert gas equalizingthe differences in the refrigerant pressure, a gas expeller, acondenser, an evaporator. and an absorber, a circulatory passage on theabsorber partly contact- 1 ing with a wall portion or the evaporator, anopening in said wall portion communicating with the said circulatorypassage and baflle means provided in the evaporator, said baflle meanscomprising a plurality of sloping baflle walls, each mounted so as toleave free a gas passage both at the higher and at the lower side of it.

5. In acontinuous absorption machine containing an inert gas equalizingthe differences in the refrigerant pressure, a gas expeller, acondenser, an evaporator and an absorber, a circulatory passage on theabsorber partly contacting with a wall portion of the evaporator, anopening in said wall portion communicating with the said circulatorypassage, and baflle means provided in the evaporator, said baflle meansbeing adapted to compel liquid refrigerant discharged from the condenserinto the evaporator to flow towards the bottom of the evaporator in sucha manner as to produce eddies in the gaseous mixture and cause mixturerich in refrigerant continuously to flow across said opening, and meansarranged for supporting circulation in the circulatory passage andoperated by pressure generated outside the absorber and evaporator.

ALEXANDER BIKERS.

